docs: def _float(value):
      """Conversion of state vector field, with automatic unit handling
      """
      if "[" in value:
          # There is a unit field
          value, sep, unit = value.partition("[")
          unit = sep + unit
  
          # As defined in the CCSDS Orbital Data Message Blue Book, the unit should
          # be the same as defined in table 3-3 which are for km and km/s for position and
          # velocity respectively. Thus, there should be no other conversion to make
          if unit in ("[km]", "[km/s]"):
              multiplier = 1000
          elif unit == "[s]":
              multiplier = 1
          else:
              raise ValueError("Unknown unit for this field", unit)
      else:
          # if no unit is provided, the default is km, and km/s
          multiplier = 1000
  
      return float(value) * multiplier